First of all hi, I've just heard about the game on the release day of v1.000 and I really like it. So far I havent made an update yet, but as I read the relase notes of 1.004 I decided to not update, although the changes to mobs are quite nice.
The reason why I havent updated yet is the new upgrade stone mechanism. The diminishing returns are something that need to be removed, as it makes upgrades useless.
I've looked through your example calculations and all I can say is: how can someone attain 400 max mana without spending all upgrades on mana. And the life increase for stone 6-10 is neclectable.
I havent upgraded a character on v1.000 yet to 10 stones, but I guess having 10/10 in health would really be overpowered as youd have an incredible amount of hp and even with less hp and a bit mana it would still be alot.
I read that you introduced those stones as a kind of punishment for death in losing the upgrades. Here are two ideas:
1) How about going with the general flow of games and introduce an exp system. Each mob grants exp and those elites could come in handy in giving out a little boost. There are a total of 30 levels for each character which results in a total of 30 possibel upgrades, but only 10 for each stat, so everyone could max out at 10/10 for hp, mp and attack. Of cource losing it all is still the penalty. In return some things need to be considered:
i) Level progression, how fast can someone reach lvl 30
ii) Balance, one could use the first 10 easy level to buff hp, making him a tank. Maybe add a limiter, lets say to get hp above lvl 3 you need to be lvl 7, or something like this, that means one can max out a stat first at lvl 27 or something like that.
iii) Maximum values. The v1.000 values might be overkill, but the 1.004 values are too low. And higher levels should never lead to lower gain.
2) Something that maybe a bit easier to add to the current death penalty system: Keep the stones, but make each upgrade costs alot less, something like this:
level 1-3: 1 stone, level 4-6: 2 stones, level 7-9: 3 stones, lvl 10: 5 stones
In return the status raise is increased at each level, so instead of ghetting less, like its in v1.004 it need to get more. Maybe something like this:
Base HP: 100 -> This will be the base for the formula, not the acutal hp on the current level, so it goes like this:
Level 1/10: +60 HP = 60%
Level 2/10: +60 HP = 60%
Level 3/10: +50 HP = 60%
Level 4/10: +90 HP = 90%
Level 5/10: +90 HP = 90%
Level 6/10: +90 HP = 90%
Level 7/10: +120 HP = 120%
Level 8/10: +120 HP = 120%
Level 9/10: +120 HP = 120%
Level 10/10: +240 HP = 240%
Thats +1050 HP = 1050%
So its 60% increase for 1 stone, 1.5x that for 2 stone, 2x that for 3 stones, and a bonus for reaching lvl 10, that is 4x the first increase for 5 stones. All in all its about the same as in v1.000. Now all thats left to do is adjust how you can reach lvl 10, what can be upgraded and how to achieve the means to upgrade.
First what can be upgrade: All 3 stats can reach lvl 10.
Second: How to reach level 10:
Just pumping stones into one stat to max it out is kind of boring, you'd just have to find the stones and use them. When you play an RPG youd have to reach higher leveld mobs to still gain exp and gain levels, while the leveling curve also raises. We cant do that here, as were playing hardcore (Ok, Diablo still does this, but whatever, its only for the really hardcore people). This is also point 3: how to achieve the means to upgrade? Since you need a lot less stones, those need to be rare, you can only find them in packs of one and only in stashes. They can also be rewards from Bosses, Missions etc, but still rare. To get all stats to 10/10 you need 28*3=84 stones. Plus when those stones are rare, youll have to choose if you either get a new hp upgrade for 3 stones or get +mp for 2 and +attack for 1 stone, for example.
As I've already said, in general RPGs, the needed exp for a level up raises, but also the exp from mobs, but in addition the curve. Since its perma death we can just remove the curve, which means we need means to gain more stones, than just 1 from a stash. We could use the raising difficulty of the mobs as a means to improve the stone reward. Aside from the overlord and his lieutenants, which should definitly give out more than one additional places could be adjusted.
There is one problem I did not account for right now, and that is that those upgrades till stay when you change the continent, so you have max hp while starting out on a tier 1 continent. This would need some balancing, but maybe I just missed something, as I havent reached the second continent yet.
In addition to those idead above, here is one for a new loaction, which would go perfectly with a stone reward for idea 2 above:
Monster Lairs
A place filled with hard to kill mobs, like the new elites. Some bosses, some minibosses, maybe even a liuetenant or an overlord. Someplace you can farm for stones, or items or whatever. I dont know if you can kill the overlord again and again, but if not, this new place could ceom in handy for nice loot and adventure. It could even contain various different stages, like a room where every mob is invicible and you have to avoid them, or a platformer in between.
I thought of something like a challenging tower, like the one in grandia, or the one in ragnarok online. No portals in between. A great place was also the ancient cave in Lufia II Rise of the Sinistrals. You can go deeper and deeper, find some nice loot, but to get out you would need a special item. In AVWW this can be a one way portal every 5 or 10 stages. I thought of it as a challenge. Of course if it was too hard, it would either need a ton of loot at the end or something special or perma death would need to changed to: if you die you lose, get ported to the entrance and the tower is sealed forever. If you manage to get out with a portal you can keep your loot, it will be gone from the tower but you can challenge it again, trying for the top this time, while all the loot on stages above the one youve gotten to is still there.